ISSN 1522-0222

Hierarchical Gaps and Subject Authority Control Processing : an Assessment

Introduction

Subject
authority control procedures vary widely from library to library. Some
processes are manual,
they have varying staffing levels, and many are
out-sourced and automated. There are two main goals behind the application of these procedures. The first
is to standardize the terminology which is used in bibliographic records. This facilitates patron access to the collections and is
significant to the fulfillment of the second of Cutter's objectives--to
allow the patron to find what a library has by subject. The secondary effect of a subject authority control procedure is to
help guide a patron from general, broad terminology to more specific,
narrower headings which he or she might need. This need for records from the upper hierarchy is not unique to
subject headings. Name headings
for subordinate bodies exhibit the same requirement, although in what is
generally a more contained environment. Name headings do not need to fit within any hierarchy other than
their own, while subject headings are part of an overall schema. The name authority record (NAR) for a subordinate body,
(e.g.,International Business Machines Corporation. Federal Systems
Division), would require that the NAR for the parent
body (International Business Machines Corporation) also be included in the
catalog. For topical subject
headings, however, this can become significantly more complex.

The
complexity of hierarchical references can be demonstrated in a variety of
ways. For example, to guide a
patron to the speciesVenturia
inaequalis (the fungal
cause of Apple Scab) requires a long chain of linkages in terminology. A gap in that linkage compromises the effectiveness of the guidance
we provide for our patrons. In
Central Washington University Library's catalog the use of the term Venturia inaequalis on a bibliographic record required the addition
of five subject authority records in addition to the one forVenturia
inaequalis to provide a full hierarchical guide. The full hierarchical path beginning atFungi
is shown in Figure 1. Items in bold are those for which the subject terminology is not on a
bibliographic record. The
authority records for those terms were added to the catalog to create a full
reference structure for a patron to follow. Thus, a patron could enter a search at any point in the hierarchy and
be led to the lone item we have that might be of interest.

A
simpler example is that of the speciesChinese
mitten crab (Eriocheir sinensis). Our
catalog lacked the authority record for the immediately higher term, the
genus,Eriocheir. Without the addition of that intervening terminology, a patron would
not get from the family,Grapsidae, to the progressively narrower terms.

In
this study we examined nine months of reports of new topical or geographic
subject headings in our catalog. We
downloaded new authority records when needed. We then examined those newly downloaded records to determine if they
needed supporting authority records based on the broader terms from those
new headings.

Literature
Review

Very
little is written on the actual subject control process.
Most of the literature available discusses the fact that authority
control is beneficial to patrons. "The
true purpose of authority control should be to help the user move
effortlessly from his/her terminology (natural language) to the terms in use
(controlled vocabulary) of the system to locate all materials (objects) that
are relevant ." (Micco, 1996: 1). A problem in academic libraries is subject authority control.
Dalrymple and Younger (1991) report that there must be informed
feedback for users when performing subject searches.

Some
literature relates to specific online catalog systems. Krieger (1990) explains that searching by subject in the Dynix system
is somewhat cumbersome because although the first search screen brings up a
see or use for reference, related terms, broad terms, and narrower terms
must be found by performing a related term command search. In a comparison between two systems, one with authority control and
one without, the authors discovered that users performed subject searches
more often than title searches (Wilkes, Nelson, 1995). The authors
point out that controlled vocabulary is a problem because if users did not
know the correct LCSH term, they would often not get results from their
search in the system without authority control. The authors state that if users had consulted the print version of
LCSH (kept near the terminals) they would have been able to determine
broader terms, narrower terms, related terms, "use fors," etc. Since many users
do not understand the idea of controlled vocabulary, it is more useful to have these references built in to the online
catalog system. Chan and Vizine-Goetz
(1998) discuss the feasibility of automatically generating a subject
validation file from OCLC. They
do not, however, discuss hierarchical issues.

Micco
(1996) explains ". the user should be able to use a hierarchical
classification to enter the system at the desired level of specificity in
the topic of their choice with the option of broadening or narrowing a
search that is not successful." (2). She continues by stating that currently (as of 1996) that option is
not available and a hierarchical system needs to be implemented for that to
occur.

Clack (1990)
addresses very briefly the need for hierarchical
records in the catalog even when the term has not been used as a subject
heading on a bibliographic record. No
further detail is given on this topic. Ludy (1985) also briefly describes the benefit of having the
authority record for the broader term, even though that term does not appear
in a bibliographic record. Michael
Gorman (2002) refers to "proceeding from the general to the specific and
following the syndetic structures of bibliographic control" as a
characteristic of a good librarian (11).

The
general concept of subject authority control, and authority control in
general, is well covered. Its
benefits are noted and recommended. Overall,
though, in none of the literature we reviewed have we found a discussion of
the frequency of the occurrence of hierarchical gaps in the authority
control process - and thus in the catalog - nor of the possible impacts
of those gaps.

Methodology

For
this study we have reviewed nine months of subject printouts from an
Innovative Interfaces, Inc. integrated library system. We looked for new topical and geographic headings only. We omitted names and titles used as subjects. We also omitted most music headings (those covering arrangements,
instrumentation, etc.) from this study, as their processing is handled by a
separate workflow.

This
review resulted in the identification of 331 new topical headings to Cattrax,
the Central Washington University Library catalog. For those new headings, we downloaded the appropriate
authority records from OCLC . We subsequently searched each of the broader terms for those topical
headings in the catalog, identifying those new broader headings that were
not represented by an authority record of their own. Those terms that required an authority record were then searched in
OCLC and the records downloaded to the catalog. The process was repeated until there were no further authority
records needing downloading into the catalog. We searched both explicit and implicit broader terms.

An
explicit broader term is one identified on the subject authority record
itself as MARC tag 550 (or 551) with a $w g. It is also known as a broader
term, or BT. Implicit broader terms are those of the type for the headingPacific
Gulf Yupik women. This
topical heading requires the subject authority record forPacific Gulf
Yupik Eskimos, because it is only on that authority that references from
variant terminology reside. Without
the authority record for this implicit broader term, references from the
variantsAlutiiq Eskimos, South Alaska Eskimos, Sugpiak Eskimos, Suqpiaq Eskimos,
etc., would not be available for our patrons. Similarly, for river valley headings and watersheds the river itself
was searched.

Broader
terms created for the specific purpose of filling a reference hierarchy,
while searched in OCLC, were not downloaded to the local catalog if
references were not needed. In
general, these types of headings take the form [Topic]
$x [Sub-topic] [Topic] $z[Geographic
subdivision]. For example,
the new heading ofAguarico River
Valley (Ecuador) had the explicit broader term ofRivers $z Ecuador. The
explicit broader term was searched in the utility, but as no broader terms
existed on the authority record for that formulated heading, the authority
record itself forRivers $z Ecuador
was not downloaded into the local catalog. Depending on the limitations of the catalog software being used by a
library, this practice would vary.

Findings

Many
of the broader terms for the new headings were already in the database. Of the 331 new headings first downloaded, 42 subsequent new authority
records (13.5%) were added. Of those 42, seven required new authority records. Of those
seven, five new records were added. Of those five, two were added; and finally, of those
two, one new authority
record was added to the database. In
all, 60 supplemental authority records were added to the database, which was
an extra 17% beyond the original new headings list of 331. Without those gaps in the hierarchy being filled, it would have been
impossible for a user to get fromLife
scientists toWomen marine
mammalogists, for example.

Contrary
to expectations, the new headings were not overwhelmingly scientific in
nature (seeAppendix). They did
include scientific terms, but also included terminology related to
agriculture, religion, technology, relationships, geographic locations,
culture, and literature.

Conclusion

Based
on this study, there are significant numbers of new subjects whose authority
records need additional authority records downloaded to fill in the
reference hierarchy. There was
no predictive subject area in which needed broader term headings are easily
identified. Some local library
systems' report capabilities might be able to identify subject headings
with broader terms not represented in the catalog by bibliographic records. Many will not be able to do so. The Central Washington University Library catalog system would not
create a report of headings for which the broader term is not also used on a
bibliographic record or not supported by an authority record above it in the
hierarchy. It will report if
the heading (MARC 1XX field) from an authority record is not found also on a
bibliographic record.

Subject
authority control procedures have been sporadic at Central Washington
University Library. Currency in
maintenance of this process could have an impact on the percentage of items
needing the additional broader term authority records.

This
study has shown, at least preliminarily, that in subject authority control
procedures there is a need to search not only the subject authority record
for the new heading itself, but also for those headings that support
hierarchical searching and the syndetic structure.

Although
it may seem time consuming to check the new heading for hierarchical gaps,
doing so will provide the links a user needs to find material on a subject
he or she is researching. It
may save time in the long run, by providing online guidance to users who do
not understand and will not learn about hierarchical relationships in
subjects.

One
of the primary goals of the catalog is to facilitate the use of the
collection by the patron. A
fully employed hierarchy must be available to the patron, to assist in the
retrieval of pertinent materials.